diff options
Diffstat (limited to 'block/blk-ioprio.c')
| -rw-r--r-- | block/blk-ioprio.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c index 8bb6b8eba4ce..4eba569d4823 100644 --- a/block/blk-ioprio.c +++ b/block/blk-ioprio.c @@ -23,25 +23,28 @@ /** * enum prio_policy - I/O priority class policy. * @POLICY_NO_CHANGE: (default) do not modify the I/O priority class. - * @POLICY_NONE_TO_RT: modify IOPRIO_CLASS_NONE into IOPRIO_CLASS_RT. + * @POLICY_PROMOTE_TO_RT: modify no-IOPRIO_CLASS_RT to IOPRIO_CLASS_RT. * @POLICY_RESTRICT_TO_BE: modify IOPRIO_CLASS_NONE and IOPRIO_CLASS_RT into * IOPRIO_CLASS_BE. * @POLICY_ALL_TO_IDLE: change the I/O priority class into IOPRIO_CLASS_IDLE. + * @POLICY_NONE_TO_RT: an alias for POLICY_PROMOTE_TO_RT. * * See also <linux/ioprio.h>. */ enum prio_policy { POLICY_NO_CHANGE = 0, - POLICY_NONE_TO_RT = 1, + POLICY_PROMOTE_TO_RT = 1, POLICY_RESTRICT_TO_BE = 2, POLICY_ALL_TO_IDLE = 3, + POLICY_NONE_TO_RT = 4, }; static const char *policy_name[] = { [POLICY_NO_CHANGE] = "no-change", - [POLICY_NONE_TO_RT] = "none-to-rt", + [POLICY_PROMOTE_TO_RT] = "promote-to-rt", [POLICY_RESTRICT_TO_BE] = "restrict-to-be", [POLICY_ALL_TO_IDLE] = "idle", + [POLICY_NONE_TO_RT] = "none-to-rt", }; static struct blkcg_policy ioprio_policy; @@ -189,6 +192,20 @@ void blkcg_set_ioprio(struct bio *bio) if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE) return; + if (blkcg->prio_policy == POLICY_PROMOTE_TO_RT || + blkcg->prio_policy == POLICY_NONE_TO_RT) { + /* + * For RT threads, the default priority level is 4 because + * task_nice is 0. By promoting non-RT io-priority to RT-class + * and default level 4, those requests that are already + * RT-class but need a higher io-priority can use ioprio_set() + * to achieve this. + */ + if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) != IOPRIO_CLASS_RT) + bio->bi_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_RT, 4); + return; + } + /* * Except for IOPRIO_CLASS_NONE, higher I/O priority numbers * correspond to a lower priority. Hence, the max_t() below selects |